Revision 9cf85473209ea8ae2b56c13145c4704d12ee1374 authored by Filip Hejsek on 28 January 2024, 04:09:17 UTC, committed by Johannes Schindelin on 17 April 2024, 20:30:01 UTC
While it is expected to have several git dirs within the `.git/modules/`
tree, it is important that they do not interfere with each other. For
example, if one submodule was called "captain" and another submodule
"captain/hooks", their respective git dirs would clash, as they would be
located in `.git/modules/captain/` and `.git/modules/captain/hooks/`,
respectively, i.e. the latter's files could clash with the actual Git
hooks of the former.

To prevent these clashes, and in particular to prevent hooks from being
written and then executed as part of a recursive clone, we introduced
checks as part of the fix for CVE-2019-1387 in a8dee3ca61 (Disallow
dubiously-nested submodule git directories, 2019-10-01).

It is currently possible to bypass the check for clashing submodule
git dirs in two ways:

1. parallel cloning
2. checkout --recurse-submodules

Let's check not only before, but also after parallel cloning (and before
checking out the submodule), that the git dir is not clashing with
another one, otherwise fail. This addresses the parallel cloning issue.

As to the parallel checkout issue: It requires quite a few manual steps
to create clashing git dirs because Git itself would refuse to
initialize the inner one, as demonstrated by the test case.

Nevertheless, let's teach the recursive checkout (namely, the
`submodule_move_head()` function that is used by the recursive checkout)
to be careful to verify that it does not use a clashing git dir, and if
it does, disable it (by deleting the `HEAD` file so that subsequent Git
calls won't recognize it as a git dir anymore).

Note: The parallel cloning test case contains a `cat err` that proved to
be highly useful when analyzing the racy nature of the operation (the
operation can fail with three different error messages, depending on
timing), and was left on purpose to ease future debugging should the
need arise.

Signed-off-by: Filip Hejsek <filip.hejsek@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
1 parent b20c10f
Raw File
git-web--browse.sh
#!/bin/sh
#
# This program launch a web browser on the html page
# describing a git command.
#
# Copyright (c) 2007 Christian Couder
# Copyright (c) 2006 Theodore Y. Ts'o
#
# This file is heavily stolen from git-mergetool.sh, by
# Theodore Y. Ts'o (thanks) that is:
#
# Copyright (c) 2006 Theodore Y. Ts'o
#
# This file is licensed under the GPL v2, or a later version
# at the discretion of Junio C Hamano or any other official
# git maintainer.
#

USAGE='[--browser=browser|--tool=browser] [--config=conf.var] url/file ...'

# This must be capable of running outside of git directory, so
# the vanilla git-sh-setup should not be used.
NONGIT_OK=Yes
. git-sh-setup

valid_custom_tool()
{
	browser_cmd="$(git config "browser.$1.cmd")"
	test -n "$browser_cmd"
}

valid_tool() {
	case "$1" in
	firefox | iceweasel | seamonkey | iceape | \
	chrome | google-chrome | chromium | chromium-browser | \
	konqueror | opera | w3m | elinks | links | lynx | dillo | open | \
	start | cygstart | xdg-open)
		;; # happy
	*)
		valid_custom_tool "$1" || return 1
		;;
	esac
}

init_browser_path() {
	browser_path=$(git config "browser.$1.path")
	if test -z "$browser_path" &&
	   test "$1" = chromium &&
	   type chromium-browser >/dev/null 2>&1
	then
		browser_path=chromium-browser
	fi
	: ${browser_path:="$1"}
}

while test $# != 0
do
	case "$1" in
	-b|--browser*|-t|--tool*)
		case "$#,$1" in
		*,*=*)
			browser=$(expr "z$1" : 'z-[^=]*=\(.*\)')
			;;
		1,*)
			usage ;;
		*)
			browser="$2"
			shift ;;
		esac
		;;
	-c|--config*)
		case "$#,$1" in
		*,*=*)
			conf=$(expr "z$1" : 'z-[^=]*=\(.*\)')
			;;
		1,*)
			usage ;;
		*)
			conf="$2"
			shift ;;
		esac
		;;
	--)
		break
		;;
	-*)
		usage
		;;
	*)
		break
		;;
	esac
	shift
done

test $# = 0 && usage

if test -z "$browser"
then
	for opt in "$conf" "web.browser"
	do
		test -z "$opt" && continue
		browser="$(git config $opt)"
		test -z "$browser" || break
	done
	if test -n "$browser" && ! valid_tool "$browser"; then
		echo >&2 "git config option $opt set to unknown browser: $browser"
		echo >&2 "Resetting to default..."
		unset browser
	fi
fi

if test -z "$browser" ; then
	if test -n "$DISPLAY"; then
		browser_candidates="firefox iceweasel google-chrome chrome chromium chromium-browser konqueror opera seamonkey iceape w3m elinks links lynx dillo xdg-open"
		if test "$KDE_FULL_SESSION" = "true"; then
			browser_candidates="konqueror $browser_candidates"
		fi
	else
		browser_candidates="w3m elinks links lynx"
	fi
	# SECURITYSESSIONID indicates an OS X GUI login session
	if test -n "$SECURITYSESSIONID" || test -n "$TERM_PROGRAM"
	then
		browser_candidates="open $browser_candidates"
	fi
	# /bin/start indicates MinGW
	if test -x /bin/start; then
		browser_candidates="start $browser_candidates"
	fi
	# /usr/bin/cygstart indicates Cygwin
	if test -x /usr/bin/cygstart; then
		browser_candidates="cygstart $browser_candidates"
	fi

	for i in $browser_candidates; do
		init_browser_path $i
		if type "$browser_path" > /dev/null 2>&1; then
			browser=$i
			break
		fi
	done
	test -z "$browser" && die "No known browser available."
else
	valid_tool "$browser" || die "Unknown browser '$browser'."

	init_browser_path "$browser"

	if test -z "$browser_cmd" && ! type "$browser_path" > /dev/null 2>&1; then
		die "The browser $browser is not available as '$browser_path'."
	fi
fi

case "$browser" in
firefox|iceweasel|seamonkey|iceape)
	# Check version because firefox < 2.0 does not support "-new-tab".
	vers=$(expr "$($browser_path -version)" : '.* \([0-9][0-9]*\)\..*')
	NEWTAB='-new-tab'
	test "$vers" -lt 2 && NEWTAB=''
	"$browser_path" $NEWTAB "$@" &
	;;
google-chrome|chrome|chromium|chromium-browser)
	# No need to specify newTab. It's default in chromium
	"$browser_path" "$@" &
	;;
konqueror)
	case "$(basename "$browser_path")" in
	konqueror)
		# It's simpler to use kfmclient to open a new tab in konqueror.
		browser_path="$(echo "$browser_path" | sed -e 's/konqueror$/kfmclient/')"
		type "$browser_path" > /dev/null 2>&1 || die "No '$browser_path' found."
		"$browser_path" newTab "$@" &
		;;
	kfmclient)
		"$browser_path" newTab "$@" &
		;;
	*)
		"$browser_path" "$@" &
		;;
	esac
	;;
w3m|elinks|links|lynx|open|cygstart|xdg-open)
	"$browser_path" "$@"
	;;
start)
	exec "$browser_path" '"web-browse"' "$@"
	;;
opera|dillo)
	"$browser_path" "$@" &
	;;
*)
	if test -n "$browser_cmd"; then
		( eval "$browser_cmd \"\$@\"" )
	fi
	;;
esac
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